1. Field of the Invention
The present invention relates to apparatus for non-destructively testing a transistor to determine the voltage the transistor can support when interrupting current flow.
2. Description of the Prior Art
Prior apparatus typically utilizes curve tracing circuits for examining transistors in the avalanche and voltage breakover regions. Such apparatus does not preclude the destructive failure of transistors whose voltage support capability has been exceeded.
When a transistor is open circuit tested, a voltage of increasing value is applied across the collector-emitter terminals until a predetermined maximum value is reached or the transistor enters voltage breakover at which time the transistor goes into a destructive failure mode.
When a transistor is operated in the dynamic state, it is desirable to determine whether or not the transistor can be operated with a given load resistance. A load line curve for such a transistor with a resistive load is given by a straight line plot of collector current versus collector-emitter voltage. However, the fact that the load line maximum voltage V.sub.CERL is less than the maximum voltage at which breakover occurs for a given transistor at zero current does not necessarily mean that the transistor will not exhibit breakover when operated with that load resistance at some finite current. None of the prior art test devices determine whether a given transistor, when operated under a given load resistance at low currents, will or will not experience breakover when subject to a given voltage at a given current without tending to destroy the transistor.